Two Reasons Why Billfish Are Catch-And-Release Only
If you're about to go on a fishing vacation in Costa Rica, you're likely looking forward to eating some delicious fresh fish daily once you've come back from your fishing excursions. However, a number of fishing tour companies distinguish between fish like tuna and mackerel and billfish, which include marlin species and sailfish -- and they release the billfish. While marlin and other billfish are certainly edible, there are two distinct reasons why the ones you catch are generally not allowed to be on your dinner plate after one of these trips.
Environmental Pressure and Declining Populations
The biggest reason, and the one driving the push to make all billfish catches release-only, is that these fish populations face tremendous environmental and industrial pressures that are causing their populations to decline. Billfish make spectacular catches; think of all the videos you've seen of large billfish leaping high out of the water when fighting a hook and line. That makes them popular catches, and they would quickly disappear from fishing grounds if everyone killed and cooked the ones they caught.
In addition to this, many billfish are killed inadvertently during commercial fishing processes -- the billfish are caught up in nets and traps meant for other fish. This too leads to a population decline. It's better for the fish species if they are marked as catch-and-release only so that their numbers don't fall drastically.
Mercury Content
Another issue is the mercury content of these fish -- it's extremely high. While you could still go to a market or restaurant in Costa Rica and find fish like marlin just waiting to be fried or baked, many tour companies do not want to touch the liability issues associated with potential mercury poisoning.
What Happens When You Catch Billfish
If you're part of a fishing excursion with a company that releases billfish, you'll still be able to bring the billfish onto the boat so its stats can be taken. Many of the fish off of Costa Rica are record-breakers, and it's nice to have a record of you catching a large fish that gave you quite a fight. However, once the numbers are recorded and the fish tagged (this lets future fishers know that if they catch that specific fish again, they aren't breaking any records), the fish are released back into the water.
If you'd like to find out which types of fish you can keep and eat during your trip, talk to fishing companies that run tours off of Costa Rica, like Go Fish Costa Rica or another business. Many offer filleting services on board, so you can step off the boat and have that fish cooked for you in one of the restaurants near the docks.
